Gable top cartons are widely employed for pourable materials in view of the many known advantages of these cartons. In particular, gable top cartons can be manufactured inexpensively from biodegradable materials, provide safe and convenient storage and facilitate pouring. Additionally, gable top cartons can be conveniently and repeatedly opened and reclosed.
The prior art includes many very desirable gable top cartons, including prior art efforts to enhance the sealing of the gable top carton, to facilitate the initial opening of the carton and/or to make the gable top carton better suited for the product to be stored therein.
One desirable gable top carton is shown in U.S. Pat. No. 4,558,814 which issued to Ihde on Dec. 17, 1985. U.S. Pat. No. 4,558,814 shows a gable top carton having first through fourth generally rectangular side panels consecutively articulated to one another, and a generally rectangular side seam flap articulated to the fourth side panel. First through fourth top and bottom flaps are articulated to the opposed ends of the first through fourth side panels respectively, while top and bottom seam flaps are articulated to the opposed ends of the side seam flap. The blank for forming the carton shown in U.S. Pat. No. 4,558,814 further comprises a reinforcing tab extending from both the side seam flap and the bottom seam flap. The reinforcing tab has no score lines and is rabbeted to define a thickness less than the remainder of the blank. The unscored reinforcing tab is folded over adjacent portions of the side seam flap and the bottom seam flap to perform a reinforcing function at the bottom corner of the resulting carton.
Another gable top carton is shown in U.S. Pat. No. 4,185,765 which issued to McLaren on Jan. 29, 1980. The blank from which the carton in U.S. Pat. No. 4,185,765 is formed also comprises four side wall panels and a glue panel consecutively articulated to one another and further comprises top and bottom panels articulated to opposed ends of the respective side panels and the glue panel. Score lines are defined on selected top and bottom panels to enable the gable top construction. However, the carton shown in U.S. Pat. No. 4,185,765 is constructed to enable a hermetic sealing, and to enable the gable top to be folded over to define a generally rectangular structure when the carton is in its fully erected and sealed condition. Another carton which is folded into a generally rectangular shape when the carton is closed is shown in U.S. Pat. No. 4,520,957 which issued to Lisiecki on June 4, 1985.
U.S. Pat. No. 3,334,779, which issued to Crawford on Aug. 8, 1967 and U.S. Pat. No. 3,189,246 which issued to Seline, Jr., on June 15, 1965 both show specific constructions for sealing the carton top and for defining the pouring spout.
Still other variations of the gable top carton are shown in U.S. Pat. No. 3,349,988 which issued to Horning, U.S. Pat. No. 4,390,121 which issued to Lisiecki, U.S. Pat. No. 4,630,733 which issued to Fear and U.S. Pat. No. 4,655,386 which issued to Billberg.
Despite the many desirable features of gable top cartons in general, and the particular structural features shown in certain of the above identified patents, it has been found that in certain instances, liquids stored in a gable top carton are likely to wick into the paperboard material generally adjacent the seams thereof. The wicking will cause small amounts of liquids stored in the prior art gable top cartons to travel upwardly through the fibrous paperboard material and into the top seal area of the carton. The wicking generally is not sufficient to cause spoilage of the product stored therein or to significantly reduce the volume. However, wicking of certain colored liquids, such as fruit juices, is known to cause a clearly visually observable discoloration along the top seal area of the prior art gable top cartons. This discoloration is noticeable and often objectionable to consumers.
Accordingly, it is an object of the subject invention to provide a gable top carton that prevents discoloration adjacent the top seal area.
It is another object of the subject invention to provide a gable top carton which prevents wicking of liquids through the paperboard material and into the seal areas of the carton.
It is a further object of the subject invention to provide a blank for forming a gable top carton that will prevent wicking of liquid material and discoloration adjacent the top of the carton formed therefrom.